Evaluation of the effect of ultrasonic degassing on components produced by low pressure die casting

Ultrasonic processing is known to be an efficient means of aluminium melt degassing with additional benefits of being economical and environment friendly. This paper describes the performance of ultrasonic degassing in preparing melt for low pressure die casting (LPDC). Efficiency of ultrasonic degassing is compared with conventional Ar rotary degassing by direct measurements of hydrogen concentration in the melt with a Foseco Alspek-H probe and by reduced pressure test in different stages of the casting process. Significant reduction in dross formation along with similar efficiency of hydrogen degassing was shown for ultrasonic degassing as compared with conventional Ar rotary degassing. Mechanical properties, microstructure and porosity level of the components produced by LPDC after both degassing techniques are determined. Results show that the components produced after ultrasonic degassing treatment have similar hardness, tensile properties, porosity level and microstructure as the components degassed with conventional Ar rotary degassing.The European Union’s Seventh Framework Program managed by the Research Executive Agency (REA;FP7/2007–2013) under grant agreement number 286344 (www.ultragassing.eu)

Transcriptional Downregulation of Rice rpL32 Gene under Abiotic Stress Is Associated with Removal of Transcription Factors within the Promoter Region

Background: The regulation of ribosomal proteins in plants under stress conditions has not been well studied. Although a few reports have shown stress-specific post-transcriptional and translational mechanisms involved in downregulation of ribosomal proteins yet stress-responsive transcriptional regulation of ribosomal proteins is largely unknown in plants. Methodology/Principal Findings: In the present work, transcriptional regulation of genes encoding rice 60S ribosomal protein L32 (rpL32) in response to salt stress has been studied. Northern and RT-PCR analyses showed a significant downregulation of rpL32 transcripts under abiotic stress conditions in rice. Of the four rpL32 genes in rice genome, the gene on chromosome 8 (rpL32_8.1) showed a higher degree of stress-responsive downregulation in salt sensitive rice variety than in tolerant one and its expression reverted to its original level upon withdrawal of stress. The nuclear run-on and promoter:reporter assays revealed that the downregulation of this gene is transcriptional and originates within the promoter region. Using in vivo footprinting and electrophoretic mobility shift assay (EMSA), cis-elements in the promoter of rpL32_8.1 showing reduced binding to proteins in shoots of salt stressed rice seedlings were identified. Conclusions: The present work is one of the few reports on study of stress downregulated genes. The data revealed that rpL32 gene is transcriptionally downregulated under abiotic stress in rice and that this transcriptional downregulation i

Increased susceptibility to cardiovascular effects of dihydrocapcaicin in resuscitated rats. Cardiovascular effects of dihydrocapsaicin

<p>Abstract</p> <p>Background</p> <p>Survivors of a cardiac arrest often have persistent cardiovascular derangements following cardiopulmonary resuscitation including decreased cardiac output, arrhythmias and morphological myocardial damage. These cardiovascular derangements may lead to an increased susceptibility towards the external and internal environment of the cardiovascular system as compared to the healthy situation.</p> <p>Methods</p> <p>Here we tested the hypothesis that the cardiovascular system in healthy rats and rats resuscitated from a cardiac arrest may be differentially affected by a transient receptor potential vanilloid type 1 agonist, by continuous intravenous infusion of dihydrocapsaicin (DHC).</p> <p>Results</p> <p>Compared to baseline, infusion of DHC caused an initial increase in mean arterial blood pressure in both healthy and resuscitated rats of 25% and 10%, respectively. Also, we observed an initial response of tachycardia in both healthy and resuscitated rats of 30% and 20%, respectively. Then, at high levels of DHC infusion (> 2.0 mg/kg/hr) we observed two single episodes of transient bradycardia and hypotension in 33% of the healthy rats, which was consistent with a TRPV1 agonist induced Bezold-Jarisch reflex. In contrast, in resuscitated rats we observed multiple episodes of bradycardia/hypotension in 100% of the rats and at a dose of DHC of 0.65 mg/kg/hr. Notably, this DHC effect could be completely blocked in the resuscitated rats by pre-treatment with atropine, a muscarinic acetylcholine antagonist.</p> <p>Conclusions</p> <p>Our results indicate that the susceptibility of the rats towards TRPV1 agonist induced Bezold-Jarisch reflex is increased in those resuscitated from cardiac arrest compared to the healthy situation.</p

A Genome-Wide Immunodetection Screen in S. cerevisiae Uncovers Novel Genes Involved in Lysosomal Vacuole Function and Morphology

Vacuoles of yeast Saccharomyces cerevisiae are functionally analogous to mammalian lysosomes. Both are cellular organelles responsible for macromolecular degradation, ion/pH homeostasis, and stress survival. We hypothesized that undefined gene functions remain at post-endosomal stage of vacuolar events and performed a genome-wide screen directed at such functions at the late endosome and vacuole interface – ENV genes. The immunodetection screen was designed to identify mutants that internally accumulate precursor form of the vacuolar hydrolase carboxypeptidase Y (CPY). Here, we report the uncovering and initial characterizations of twelve ENV genes. The small size of the collection and the lack of genes previously identified with vacuolar events are suggestive of the intended exclusive functional interface of the screen. Most notably, the collection includes four novel genes ENV7, ENV9, ENV10, and ENV11, and three genes previously linked to mitochondrial processes – MAM3, PCP1, PPE1. In all env mutants, vesicular trafficking stages were undisturbed in live cells as assessed by invertase and active α-factor secretion, as well as by localization of the endocytic fluorescent marker FM4-64 to the vacuole. Several mutants exhibit defects in stress survival functions associated with vacuoles. Confocal fluorescence microscopy revealed the collection to be significantly enriched in vacuolar morphologies suggestive of fusion and fission defects. These include the unique phenotype of lumenal vesicles within vacuoles in the novel env9Δ mutant and severely fragmented vacuoles upon deletion of GET4, a gene recently implicated in tail anchored membrane protein insertion. Thus, our results establish new gene functions in vacuolar function and morphology, and suggest a link between vacuolar and mitochondrial events

Devenir des femmes de moins de 30 ans prises en charge pour une lésion intra-épithéliale de haut grade du col utérin non traitée

International audienceObjectivesTo assess the probability of spontaneous regression of high grade cervical intraepithelial neoplasia (HGCIN) in women under 30 and the predictive factors for such evolution.MethodsWe conducted a bicentric retrospective study. A total of 98 patients under 30 and with untreated HGCIN were included from 01/01/2010 to 31/12/2019. For each patient, the initial clinical and colposcopic characteristics were systematically documented. In compliance with French guidelines, these patients were offered repeated 6-months colposcopic follow-up for 2 years. The endpoint was the occurrence of spontaneous regression of the HGCIN defined by normalization of colposcopy, and/or a negative biopsy and/or a negative HPV test or histological regression to low grade CIN, or a colposcopy showing simple minor abnormalities requiring no biopsy.ResultsSpontaneous HGCIN regression was observed in 37/98 patients. The median follow-up was of 16 (10.5–24.3) months. Predictive factors for spontaneous regression were: minor initial cytological abnormalities (HR = 3.4; 95% CI: 1.02–11.05) and grade 1 atypical transformation at initial colposcopy (TAG1) (HR = 2.3; 95% CI: 1.1–4.7).ConclusionBefore 30, the probability of spontaneous regression of HGCIN exists but remains low. Predictive factors for such evolution are minor initial cytological abnormalities and TAG1 colposcopic impression.ObjectifsÉtudier la probabilité de régression et de guérison spontanée d’une lésion intra-épithéliale de haut grade (LIEHG) du col utérin, chez les femmes de moins de 30 ans.Matériels et méthodesNous avons mené une étude bicentrique, rétrospective, du 01/01/2010 au 31/12/2019. Au total, 98 patientes de moins de 30 ans, ayant été surveillées pour une LIEHG ont été incluses. Pour chacune d’elles les caractéristiques cliniques et colposcopiques initiales étaient systématiquement précisées. Selon les recommandations, ces patientes ont bénéficié d’un suivi colposcopique tous les 6 mois pendant une durée maximale de 2 ans. Le critère de jugement principal était l’obtention d’une guérison, définie par la normalisation de la colposcopie, et/ou l’obtention d’une biopsie négative et/ou d’un test HPV négatif ou d’une régression, définie par la mise en évidence histologique d’une lésion intra-épithéliale de bas grade, ou par une colposcopie mettant en évidence de simples anomalies mineures ne motivant pas la réalisation d’une biopsie.RésultatsUne guérison ou régression a été mise en évidence chez 37/98 patientes. La médiane de suivi était de 16 (10,5–24,3) mois. Les facteurs prédictifs de guérison/régression étaient : des anomalies cytologiques initiales mineures (HR = 3,4 ; IC95 % : 1,02–11,05) et une transformation atypique de grade 1 à la colposcopie initiale (HR = 2,3 ; IC95 % : 1,1–4,7).ConclusionAvant 30 ans, la probabilité de régression ou de guérison d’une LIEHG existe mais reste limité et dépend de la sévérité des anomalies cytologiques et de l’impression colposcopique initiales